Keyboard for musical instruemnts, in particular for accordions



March 18, 1958 K. SCHERER 2,826,953

KEYBOARD FOR MUSICAL INSTRUMENTS, IN

.6 Sheets-Sheet 1 PARTICULAR FOR ACCORDIONS Filed Feb. 29, 1956 19 51 25 INVENTOR.

March 18, 1958 K. SCHERER ,8

KEYBOARD FOR MUSICAL INSTRUMENTS, IN PARTICULAR FOR ACCORDIONS Filed Feb. 29, 1956 e Sheets-Sheet 2 22 4a 47 11 2s 57 9 10 2b 1 1 k IIIIII/I/ IN VEN TOR.

Kan/6W 2,826,953 S, IN 6 Sfieets-Sheet 3 K. SCHERER R MUSICAL INSTRUMENT PARTICULAR FOR ACCORDIONS KEYBOARD F0 March 18, 1958 Filed Feb. 29, 1956 INVEN TOR.

March 18, 1958 K. SCHERER 2,826,953 KEYBOARD FOR MUSICAL INSTRUMENTS, IN

PARTICULAR FOR ACCORDIONS Filed Feb. 29, 1956 6 Sheets-Sheet 4 K. SCHERER 2,826,953 KEYBOARD FOR MUSICAL INSTRUMENTS, IN

March 18, 1958 PARTICULAR FOR ACCORDIONS 6 Sheets-Sheet 5 FilecLFeb 29 1956 IN V EN TOR.

March 1958 K. SCHERER 2,826,953

KEYBOARD FOR MUSICAL INSTRUMENTS, IN PARTICULAR FOR ACCORDIONS Filed Feb. 29, 1956 6 Sheets-Sheet 6 INVEN TOR.

WW BY WW United States Patent KEYBOARD FOR MUSICAL INSTRUMENTS, IN PARTICULAR FOR ACCORDIONS Karl Scherer, Trossingen, Germany Application February 29,1956, Serial No. 568,670 Claims priority, application Germany March 4, 1954 18 Claims. (Cl. 84-376) The present invention relates to a keyboard for musical instruments and in particular for accordions which comprise a plurality of keys, a key enclosure with a key mounting disposed therein and the key wires connecting the air flaps with the keys.

Accordions are known in which the keys are mounted directly on the key enclosure of the instrument and in particular usually by means of an axle extending through the entire line of keys. This long axle with its plurality of bearings must be removed for taking ofi the keys and then reinserted again, an expedient which leads to appreciable ditficulties. In addition the axle must penetrate at least one wall of the enclosure in order to permit gripping of said axle with a tool. This requires a perforation of the enclosure wall, thereby disturbing the smooth surface thereof.

It is, therefore, one object of the present invention to provide a keyboard for musical instruments which is of such construction as to the mounting of the keys in the keyboard enclosure combined with the structure of the keys which brings about a great simplification of the work involved for assembly and disassembly of the keyboard, particularly in the direction that not a complete dismantling of the keyboard is required in each case, and also that perforations of the keyboard enclosure are avoided.

It is another object of the present invention to provide a keyboard for musical instruments in which the keys and their bearings, as well as the key wires connecting the keys and the air flaps are divided into groups and each of said groups is removably secured to a base plate mounted on the instrument. The division into groups may be extended so far that it is theoretically possible that each key with its bearing is mounted separately on a complementary base plate.

It is still another object of the present invention to provide a keyboard for musical instruments of the type stated in the last mentioned object, in which the base plates are secured to the wall of the instrument which carries the keyboard and in particular in connection with an accordion, on the back wall of the keyboard enclosure. It is of advantage not to mount the base plates on the back wall throughout their entire length, rather two special rails are provided which are disposed in the longitudinal direction of the keyboard enclosure which are secured to the back wall of the latter about below the ends of the keys and secure the base plates in position. Any warping of the wall which carries the keyboard is thus not transmitted to the bearings for the keys.

It is yet another object of the present invention to provide a keyboard for musical instruments of the type set forth in the last mentioned object in which the rail disposed under the free ends of the keys forms a notch which receives slidably a projection of the base plate. The opposite edge of thebase plate rests on a second rail disposed below the other end of the keys. A locating pin connection disposed between the base plate and the rail for each group of the keys fixes the position of the base plate in the keyboard enclosure and the position of the key groups relative to each other. The base plate is secured to the rail by releasable means. The keys may be mounted between the leg portions of U- shaped bearing blocks made preferably of metal, which leg portions project through a series of parallel disposed slots of the base plate and are secured thereto. The keys of one base plate coordinated to one key group are pivotally connected to the base plate by means of a common axle extending through the keys and the leg portions of said bearing blocks. The mounting may be also arranged in such manner that an integral group of hearing blocks preferably made of artificial material is connected with the base plate, the keys being mounted between the said bean'ng blocks by means of a single axle which rests in grooves of the bearing blocks and projects through the keys, which axle is retained in this position by means of a bridge comb secured to the base plate and covering said grooves. In case the bearing blocks are made of artificial material, the grooves are open at one side. The mentioned bridge comb may in some instances secure the bearing blocks to the base plate.

It is still a further object of the present invention to provide a keyboard for musical instruments in which the keys are mounted on a base plate and in which the base plates form a bridge-like recess below the key ends for the mounting of the keys and in which the keys which rest on elastically compressible discs or a band disposed on said recess are retained over said recess resiliently by means of screws or the like which extend through bores provided in said recesses and anchored in said keys. This keyboard mounting avoids the provision of an axle and permits the removal of each key of the group from the base plate upon removal of the latter from the keyboard enclosure.

It is yet a further object of the present invention to provide a keyboard for musical instruments in which the keys of the keyboard comprise a key body made of wood or artificial material and a cover extending over the playing surface and the side faces of the keys, which cover is preferably made of artificial material and is connected with the key body. The key wire is retained in the U-shaped cross section of the key body. The cover for the key body is equipped with projections which extend between the leg portions of the U-shaped key body which serves the purpose to connect the cover to the key body by means of pins or the like, and if necessary, additionally by a gluing operation.

It is also a still further object of the present invention to provide a keyboard for musical instruments in which in one embodiment of the structure the key wires which project through the key bodies are glued at their ends in slots of a crank-shaped portion of the base plate. On the portion of the crank of the base plate which extends parallel to the main plane of the base plate is disposed opposite the wall of the keyboard enclosure, which carries the keyboard, a strip preferably made of pasteboard or the like which has slots of a width greater than the slots of the crank-shaped portion of the base plate. A piece of cloth which encloses the path of the key wire end is disposed inside of the slots of the base plate and of the superposed strip, which piece of cloth is preferably secured to the superposed strip by means of gluing. If desirable a similar guide may be provided without any difficulty also for the half-tone keys.

It is yet another object of the present invention to provide a keyboard for musical instruments in which a ledge is provided in the base plate to operate as a guide for the spring ends for the keys which ledge is equipped with grooves and is preferably set in the base plate. This ledge is preferably adjustable as to its height in order to control the spring force. This adjustment may be' Patented Mar. 1s, 1.958.

brought about, for instance in such manner, that a ledge coordinated to a key group is tiltably mounted and adjustable by means of a pin which projects through the wall of .the keyboard enclosure and is settable by means of a movable wedge. Instead of providinga singular ledge which is coordinated'to several keys, it is possible to provide guide elements coordinated to a single-key which guide elements function in the same manner, so that the spring force may be adjusted individually for each key and the key pressure adjusted accordingly;

It is also a still further object of thepresent invention to provide a keyboard for musical instrument in which in accordance with another embodiment of the invention the keys are mounted on one of their ends betweentwo legs of a U-shaped block which surround the key body and the legs of which U-shaped block project through parallel disposed slots of the base plate and are secured to the latter. The key wires thus do not project through the key body and the .key bodies are guided in similar manner at their free ends as provided for on the other end between said blocks. The guidance of the keys at their free'end is of importance, because the keys are not supposed to engage each other, rather equal narrow spaces are to be provided between the keys and the latter are supposed to move without friction. If the keys are guided by the key wire, the latter is slightly bent in order to properly align the keys. In this manner, however, some friction may occur'in the guidance of the key wire which is not desirable. In the mentioned other embodiment of the present invention it is possible to provide a height for the leg portions of the blocks complementary to the stroke of the keys, thereby improving the guiding characteristics and the blocks may be made of a suitable material which has favorable sliding characteristics and which also permits an easy and exact alignment of the leg portions of the blocks. Since both leg portions of the blocks may be aligned and a selective play between the key body and the guide may be arranged, a more preferable alignment is brought about compared with that embodiment in which the key wire must be bent for alignment of the keys. The blocks may be also made of another material than that of the base plate, for instance, of brass, while the material of the base plate may be a light metal. Furthermore, the arrangement of the keyboard in accordance with the present invention brings about the advantage that the key body may be solid, for instance, of wood, because the key wire does not project ther'ethrough. The key body may be also made of a thermoplastic material which in its formation permits arrangement of the bore in the key body for the axle. The thermoplastic material may be any material which may be made to a cast formed by an injection process or which may be pressed, and in particular may be not only an artificial material but also a metal. By forming the key body in the stated manner, according to which the bore for the axle is not provided afterwards, but by inserting a core into the form, it is possible that in each of the key bodies the actual bore assumes always the same position in relation to the key body and, thereby, also to the block. The necessity for aligning the keys due to diflferent sets in the axle bores is in this manner eliminated.

It is yet an additional object of the presentinvention to provide a keyboard for musical instruments which includes a still further improvement in the guidance for the keys which aim is achieved by arranging on the key body at least within the range of the complementary block diverging guide faces towards the base plate and by providing an outwardly directed projection on the leg portions of the block within the moving range of said side faces. This projection is of such height that the mentioned guiding faces are moved within the range of the complementary projection duringmovement of the key body, while the key body in 'its normal position is guided by the upper ends of the blocks. In order to achieve'the same result it is possible to provide the side faces of the blocks with receesses instead of projections in such manner that the side faces of the key body do not find any friction faces upon pressing down of the key. A diverging formation of the guide faces of the key bodies may easily be obtained during the forming of a-'-key ifthey consist of thermoplastic material. Due to such formation of the key body and of the blocks it is brought about that the side faces of the key body which in normal position of the key engages the sides of the blocks, move past the-projections or recesses of the blocks upon pressing down the key, so that the side faces do not create any frictional resistance. On the other hand, the keys have due -'to such guiding means of the upper ends of the sides an exact spacing from each other. In this manner it is possible to provide a perfect guidance without the use of an axle cloth. The; key body may be (if-course formed in any desirable-manner and may, for instance, have a profile which permits oran easy and safe mounting of the key cover over the key body. A filler layer is advantageously provided between' the leg portions of-the blocks on the base plate as a limiting means for the key stroke.

With thes'e'aiid other objects in view which will become apparentin the following detailed decsription, the present invention will be clearly understood in connection with'the accompanyingdrawings, in which:

'Figure 1 is a perspective front view of an accordion, one-of the base plates with the keys, key wires, air flaps andkey bearings coordinated thereto being removed;

Fig. 2 is a top plan view of a base plate with all the parts secured thereto at enlarged scale;

Fig. 3 is a fragmentary section through the keyboard enclosure showing a first embodiment of the key mount- Fig. 10 is a section through a key along the lines XX of Fig. '8, shown at enlarged scale; Fig. II is a perspective side view of the guide of the end for the key wire;

Fig. 12 is a section along the lines XiL-XII of Fig 4; Fig. 13 is aperspective front view of another embodiment of the accordion in which one of the base plates with the coordinated keys, the key mounting and the air flap have been taken out;

'Fig..14 is a fragmentary section through the keyboard enclosure showing the key mounting;

Fig. 1-5 is a perspective top view of a base plate with the key mounting;

Fig. 16 is a side elevation of a single key with its mounting means;

Fig. 17 is a 'cross's'ection through a key with the solid key body and its guide; Fig. 1 8 is a c'ro's's'section through a key with an H- shaped key body and it's guide;

Fig. '19'is a'per'spective side view of the key body shown in Fig. '18;

Fig. 20 is a perspective side view of a key body with diverging s'idefa'ces;

Fig. 21 is a perspective side view of a key guide for the key body shown in Fig. 20;

Fig. 21a is a perspective side view of another embodiment of the key guide;

Fig. 22 is a cross section through a key having a key body with diverging side faces in combination with the coordinated key guide;

Fig. 23 is a perspective side view of the key body shown in Fig. 22;

Fig. 24 is a perspective side view of a key guide shown in Fig. 22;

Fig. 25 is a side elevation of the key shown in Fig. 22 together with its mounting; and

Figs. 26, 27 and 28 show respective cross sections of key bodies having diverging side faces.

Referring now to the drawings and in particular to Figs. 1 to 12, the accordion comprises in known manner a treble side 1, a base side 2 and the expandable and contractible portions 3 which connect with the treble side 1 with the base side 2. The filler 5 is disposed on the treble side 1 below the cover 4, which filler 5 is equipped with openings 6 for passing of air and the reed cells 7 (Fig. 3) are arranged below the openings 6.

The air passage through the openings 6 is controlled by means of air flaps 8 which are connected with the keys and 11, respectively, by means of key wires 9. The keys are mounted on the wall 12 of the keyboard enclosure 12', which wall 12 carries the keys. It is to be understood that the arrangement described so far is of conventional nature.

In the embodiment disclosed in Figs. 1 to 12 the keys 10 and 11, the key mounting and the key wires 9 which connect the air flaps 8 with the keys 10 and 11 are divided into groups and each group is releasably mounted on a base plate 13 which is releasably secured to the wall 12. The base plates 13 are supported by rails 14 and 15 which are disposed lengthwise in the keyboard enclosure 12' in such manner that they bridge over the wall 12. The rail 14 is preferably designed of Z-cross section so that one edge 16 of the base plate 13 may be inserted into the rail 14. The opposite end 17 of the base plate 13 rests on the rail 15 and is secured thereto by means of screw bolts 18. It is of advantage to provide there a locating pin connection in order to secure the base plate 13 in its position during assembly of the accordion. The rail 15 may be provided with locating pins 19 which extend into corresponding bores 29 of the base plate 13.

The mounting of the keys may be arranged in different manner. In the embodiment shown in Figs. 3 and 4, the base plate 13 is equipped with a plurality of parallel dis posed slots 21. Blocks 22, preferably made of metal having U-cross section, are inserted from below into these slots so that the legs of the U project therethrough, the blocks 22 being secured to the bridge portions 23 disposed between the slots 21. The keys 10 and 11 are mounted between the leg portions of the U-shaped blocks 22 and in particular are the keys of one group pivotally mounted by means of an axle 24 which extends through bores of the legs portions of the blocks 22 as well as through bores of the keys 10 and 11.

The keys comprise, as particularly shown in Figs. 9 and 10, a key body 25, for instance of wood or artificial material, and a key cover 26 which is preferably made of artificial material. The key body 25 is of U-shaped cross section and the key wire 9 projects therethrough. The key cover 26 covers the key body 25 due to its cup shape. In order to secure the key cover 26 to the key body 25, the key cover 26 is equipped with projections 27 or the like which extend into the space between the leg portions of the U-shaped key body 25. The securing of the key cover 26 to the key body 25 is brought about in particular by gluing and also by means of pins 28 which extend through the leg portions of the key body 25 and through the projections 27 of the key cover 26.

' 6 The cup shaped key cover 26 has on one side recesses 29 through which the pins 28 may be inserted.

If full tone keys are provided, the key wires 9 extend through the keys and are cranked at their ends 9'. These cranked ends 9 are received in particular in the slots 3i! of the base plate 13.

The base plate 13 has a Z-shaped bend or is forming a step on which the ends 9 of the key wire 9 rests, thus forming an edge portion 13' which is disposed parallel to the main plane of the base plate 13. A plate 13" is secured to the main portion of the base plate 13, which plate 13" extends parallel to and spaced apart from the edge portion 13 and the edge 16 of the plate 13" is received below the raised portion of the rail 14. The slots 30 start in the main portion of the base plate 13 and continue into the edge portion 13' of the base plate 13 over the vertical connecting portion which connect the edge portion 13' with the main portion of the base plate 13. A ledge 31, for instance of cardboard, is provided below the edge portions 13, which ledge 31 is equipped likewise with slots 32 complementary to the slots 31'] of the edge portion 13, however, with the exception that the slots 32 are wider than the slots 30 of the edge portion 13' (Fig. 12). The channel formed by a pair of such slots 39, 32 for guiding the key wire end 9' is equipped with a lining of soft material 33, for instance cloth material, which is known per se for such guides. The cloth material is secured to the ledge 31, for instance by gluing. Due to the difierent width of the slots 30 and 32, respectively, it is possible that the guide for the key wire end 9 is widened from top to bottom, so that the key wire end 9, upon pressing down of the coordinated key, is freed and during its upward movement, while it was engaging the cloth material 33 during its normal position.

A second strip 34 of soft material, for instance felt, is disposed adjacent the edge 16 of the base plate 13, which strip 34 serves as abutment means for the key wire end 9, thereby limiting the key stroke.

In the embodiment of a key mounting shown in Figs. 5 and 6 an integral group of bearing blocks 35 preferably of artificial material is secured to the base plate 13, for instance at 36. The keys are mounted between the blocks 35 by means of an axle 37 which is received by grooves 38 of the blocks 35. The axle 37 is retained in its position by means of a bridge comb 40 which is secured to the base plate 13, for instance at 39, and which "bridge comb 40 may be made of metal and the bridging portions 41 of which cover up the grooves 38.

In accordance with a still further embodiment of the key mounting, the base plate 13 is equipped with a bridge shaped curved portion 42 which is advantageously of half circular cross section, in order to mount the keys thereon for tilting movement (Fig. 7). The keys 10 and 11 are supported by said curved portion 42 by means of a screw bolt 43 or the like, which projects through a bore 44 of the curved portion 42 and is releasably anchored in the key body 25. An elastic compressible intermediate member 45 is disposed between the key body 25, which projects below the key wire 9, and the curved portion 42. A spring 46 is also disposed on the screw bolt 43 or the like between its head and the under face of the curved portion 42, so that the key is pressed resiliently to its support and also'receives the required freedom of movement for the tilting action.

The keys 10 and 11 are equipped in conventional manner with springs 47 (Figs. 3, 5 and 7), which springs retain the keys in their normal position in which the air flaps 8 which are connected with the keys 10 and 11 by means of the key wires 9 rest on the air opening 6 of the filler 5. The springs 47 may be secured, for instance by means of a pin 48 in a lateral recess 49 of the key body 25. A ledge 51 supporting one leg of the wire spring 47 is arranged on the base plate 13 and preferably set in a lowered portion 50 thereof, which ledge ,7 His equipped with gr'ooves 52 adapted to re'ceive one leg of the wire springs'4 7.

Fig. disclosesan'arrang'ement whichp'ermits the control of the force exerted by the spring 47. In order to achieve this end, the ledge 51 is pivotally mounted at 52'. The keyboard carrying wall 12 has bores 53 which receive pins 54. The latter are pressed against the ledge 51 by means of a longitudinally slidable wedge member 55 against the force of the spring 47, so that the spring force, and thereby, the required key pressure is increased. If a reduction of the spring force is desired, the wedge member 55 is moved in opposite direction. A cover plate'56 disposed on the outside of the wall 12 covers the wedge member 55, which cover plate 56 has one or more cut outs in such arrangement that the wedge member 55 may be properly moved, without removing the cover plate 55. v

If in the case of half tone keys '11 the key wire 9 does not extend through the keys but terminates inside thereof, the key body of the half tone keys 11 is equipped with a downward projection 57. A ledge 58is disposed on the base plate 13 opposite the projections 57, which ledge '58 is made of soft material and serves as abutment means during operation of the half tone keys.

Referring now again to the drawings, and inparticular to Figs. 13 to 28, the accordion disclosed in Fig. 13 comprises a treble part 101, a base part 102 and..an.expandable and contractible portion 103 which connects the treble part 101 with the basepart 102. In the treble part 101 a filler 105 is provided below the .cover 104, which filler 105 is equipped with openings 106for passing of air therethrough, the reed cell 107 (Fig. 'l4)-being disposed therebelow.

The passage of air through'the openings -1t16'is controlled by air flaps 108 which are connected with the keys 110 and 111 by means of key wires 109. The keys are mounted on the keyboard carrying wall 112 of the keyboard enclosure 112'.

The keys 111) and 111, the key mounting :and:the:air flaps 108 together with the key wires 1119 are "divided into groups andeach groupis releasablymdunted one base plate 113 which is secured toth'e keyboard enclosure 112. The base :plates 113 are .releasably, secured to lengthwise disposed rails 114' andv 115 which are mounted on the keyboard enclosurei 112.

In order to mount thekeys, each base .plate 113 is equipped with a plurality of .parallel disposed slots '121 which receive from 'bel'owthe'leg portions of .u shaped blocks 122, preferably of'metal, -which blocksare secured to thebridgeportions 123 disposeibetween the slots "121. The keys 110 and 111 are mountedzbetweenatheslegpon tions of the blocks 122 andthe keysiare .pivotally connected to the blocks by means of anraxle 124 which extends through bores of the leg'portions o f-the blocks 122 as well as of the keys 110 and 111.

The keys 11!) comprise a key body 159 andLa cupshaped cover 160 secured to'said key body. In accordance with the present invention the .key bodies ':159.of the keys 110 are mountedat their end opposite their-support in the blocks 122 between two leg. portions 161 01 U-shaped blocks 161. The latter. enclosethekey body 159 and their leg portions extend through I a plurality of parallel disposed slots 1626f the base plate 113. 'The blocks 161 are additionally secured-tome bridgeportions 163 of the base plate -1'1 :3,-w'hich bridge portions 163 are disposed between the-slots 162. layer-164 offelt or the like is disposed on topof thebridge portions 163,

which layers 154 are ad-ap-tedto provide a damping effect upon pressing down the key body 159.

The keys 11d areyequipped in --conventional m'anner with a wire spring l fl whieh m'aybe securedi-n -a recess 149 of the key body by means of-a pin 148. On the base plate 113 .and particularly set-in 'a'recess 150 thereof is ale-tige 1 51 adap'tedas a spring guide, which ledge 151 is equipped with grooves 152 in which one leg of the wire springs 147 is received (Fig. 15).

-A key with a solid key body 159a is disclosed in Fig. 17, which key body 15% supports a cup-shaped cover 160a, while in Figs. 18 and 19 a key body 15% of H- shaped profile is shown which supports a cup-shaped cover 16%.

Figs. 20 to 28 relate to variations in. which the key bodies have side faces which are diverging downwardly.

The key body 159g shown in Fig. 20 isequipped with side flanges 171 which diverge downwardly towards the base .plate 113. Blocks 172 are provided for guiding the keys in connection with such key bodies 159g, the leg portions 173 of the blocks 172 having within the moving range of'the flanges 171 of thecoordinated key body 159g outwardlyprojecting portions 174. The key body 159g is guided in the'no'rmalposition of the keys by the uppernon-projectingparts of the leg portions 173.

The blocks may be inserted intothe baseplate 1 .3, if thebridge portions 163 are kept so narrow that they may project between the-upper non-projecting parts of the leg portions 173 of the blocks 172. The latter are guided in this case-in the base'plate 113 by the outer edges of the slots-162 through which they project.

Figs. 22 to 25 disclose an embodiment in which the key body 159c which is covered by the cup-shaped cover 160C is equipped with guiding flanges 166 diverging towards the base plate 113, which guiding flanges 166 are of greater height Within the range-of the coordinated blocks than that of its adjaeentportions and for this reason project further sidewardly. The guide flanges form in their portions of greater height hammer head-like Parts 167.

Withinthe range-of'those parts 167 of the key body 1590 aretheleg portions 165 of-the block 165 equipped with a recess 168, so that in normal position of the key the hammer head-like parts 167 which arepreferably rounded up at their ends'are disposed between the remaining bridge portions-169 of the blocks 165, while the keys upon pressing down the latter pass by the recesses 168, so that no friction may occur.

It is of course also possible toprovide the leg portions 173 of the blocks 172, which leg portions 173 are equipped with projections 174, with recesses similar to those provided for in the blocks 165 (Fig. 21a In'this case, keys with a key body having the shape of the key body 1590 (Fig. 23) are guided by the blocks172.

Figs. 26, 27 and 28 show other cross sections of key bodies 15%, 1592 and 159 respectively, which have side flanges diverging towards thebase plate.

All key bodies 159a to 159g maybe made of thermoplastic material so that during formation thereof the bore 179 of the key body for theaxlemay be formed or molded simultaneously.

While I have disclosed several embodiments of the presout invention, it is to be understood that these embodiments are given .by example only and not in a limiting sense, the scopeof the present inventionbeing determined by the objects and the claims.

I claim:

1. In a musical instrument in particular an accordion, a keyboard wall, a'plurality of base plates, means for releasably securing said base plates along said keyboard wall, each of said-base plates being disposed sideways to the adjacent of said base plates, a plurality of reed cells disposed inside of said instrument, a filler board having a plurality of openings, each of said openings being coordinated to and cooperating with one of said reed cells, an airflap disposed on top of each of said openings to assume a closing and iifted-position, respectively, each of said base plates including a predetermined number of key mounting means, ankey mounted for tilting movement on each of'said key mounting means, a key wire connecting each of said keys with one of said air flaps coordinated thereto for common tilting movement therewith, said keys, said key wires and said air flaps corresponding with said keys mounted on one of said base plates constituting one group individually releasable together with the corresponding base plate from said keyboard wall, and the said keys combined from all said groups constituting the entire keyboard.

2. The musical instrument, as'set forth in claim 1, in which said means for releasably securing said base plates to said keyboard wall are outside of the range of said keyboard, thereby, permitting the mounting of the predetermined number of said keys with their corresponding key wires and air flaps on each of said base plates prior to the securing of the latter to said keyboard wall.

3. The musical instrument, as set forth in claim 1, which includes two rails disposed longitudinally parallel to and spaced apart from each other over the entire length of said keyboard wall, and means for rigidly securing said rails to said keyboard wall, said base plates being releasably secured to and bridging said rails.

4. The musical instrument, as set forth in claim 3, wherein one of said rails has a ledge formation adapted to receive one longitudinal edge of each of said base plates, the other longitudinal edge of each of said base plates resting on the other of said rails, and said means for releasably securing said base plates along said keyboard wall being applied to said other of said rails and comprising screw means and locating pins disposed between the latter.

5. The musical instrument, as set forth in claim 1, which includes a block member coordinated to each of said keys, said block member being of U cross section and the said keys being disposed each between the legs of one of said blocks, and in which the said base plates each have a plurality of parallel disposed slots receiving the leg portions of said blocks to secure said blocks to the corresponding of said base plates and an axle coordinated to each of said base plates, said axle extending through the said keys mounted on the corresponding of said base plates as well as through the leg portions of the said blocks carried by said base plates, in order to pivotally mount the said keys coordinated to the corresponding of said base plates on the latter.

6. The musical instrument, as set forth in claim 1, which includes an integral group of bearing blocks secured to each of said base plates, said blocks having longitudinally disposed vertical grooves, an axle received by said grooves, said axle extending through the said keys, the latter being disposed between the said blocks, a bridge comb member arranged on top of said blocks and secured to said base plate, thereby retaining said axle in said grooves.

7. The musical instrument, as set forth in claim 1, in which each of said base plates is provided with an upwardly bent portion adapted to serve as a mounting for said keys, an elastically compressible intermediate member disposed between the said keys and said bent portion and means for retaining said keys in supported position.

8. The musical instrument, as set forth in claim 1, in which the said keys comprise a key body and a key cover, said key body being of U-cross section and receiving said key wire.

9. The musical instrument, as set forth in claim 8, in which said key cover is of cup shape and surrounds the said key body and in which the said key cover has a projection extending into the space defined by the said U- shaped key body, and pins extending through the leg portions of said U-shaped key body and through said projection of said key cover, in order to retain said key cover on said key body.

10. The musical instrument, as set forth in claim 9,

wherein said keyboard comprises a first set of full tone keys and a second set of half-tone keys, and in which said, base plate has a cranked portion disposed along one of its longitudinal edges, the said cranked portion having a plurality of parallel, crosswise disposed slots, and said key wires connected with said first set of keys extend through the latter and at their end into said slots of the cranked portion of said base plate.

11. The musical instrument, as set forth in claim 10, which includes a strip disposed longitudinally below said cranked portion of said base plate, the said strip having slots of greater width than that of said cranked portion of said base plate and a lining of soft material being disposed in the said slots of the said strip, which lining encloses the path of the end of said key wire.

12. The musical instrument, as set forth in claim 1, in which said base plate includes a ledge member having a plurality of crosswise disposed parallel grooves, each of said grooves being adapted to receive one end of a spring wire coordinated to each of said keys, said ledge member being secured to the said base plate.

13. The musical instrument, as set forth in claim 12, which includes means for adjusting the height of said ledge member.

14. The musical instrument, as set forth in claim 13, in which said ledge member is pivotally mounted on said base plate and pins projecting through said keyboard wall opposite said ledge member, and wedge means in said wall for adjustingly positioning said pins.

15. The musical instrument, as set forth in claim 1, which includes a guiding means for said keys disposed at the end of said keys opposite said key mounting means, said guiding means comprising a plurality of blocks of U cross section, the space defined by the leg portions of said blocks receiving said respective keys, and the said base plates having a plurality of parallel disposed slots through which the leg portions of said block members project, and means connecting the said last mentioned blocks to said base plate.

16. The musical instrument, as set forth in claim 15, wherein each of said keys comprises a key body and a key cover therefor and in which each of said key bodies has lateral flange portions diverging downwardly towards the said base plate at least within the range of said corresponding blocks, and in which the leg portions of the said blocks have a wider part at least within the range of operation of said flange portions of said key body.

17. The musical instrument, as set forth in claim 15, wherein each of said keys comprises a key body and a key cover therefor and in which each of said key bodies has lateral flange portions diverging downwardly towards the said base plate at least within the range of said corresponding blocks, and in which the leg portions of said blocks have an opening at least within the range of operation of said flange portion of said key body.

18. The musical instrument, as set forth in claim 1, in which each of said keys comprises a key body and a key cover therefor and in which said key body is made of thermoplastic material, in order to permit during its molding simultaneously the formation of a bore, adapted to receive an axle extending through all said key bodies mounted on each of said base plates.

References Cited in the file of this patent FOREIGN PATENTS 348,871 Italy June 2, 1937 351,954 Italy Aug. 27, 1937 657,228 Germany Feb. 26, 1938 

